Fix: Add errno check to strtol for detecting out-of-range width values

[ismaileneskucuk]

Resolves #614
Added errno = 0 before parsing and an ERANGE check afterwards to safely exit with an error message when out-of-range width values are provided.

[nwellnhof]

In addition, you have to check that the input string isn't empty, in which case unparsed[0] will be 0 despite no conversion being performed. Then we should reject negative or non-positive widths.

[ismaileneskucuk]

Updated the logic to use unparsed == argv[i] to catch empty inputs.

Also added a check to reject < 0 values. 0 is kept valid since it is documented as the nowrap behavior.

Let me know if anything else is needed.